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PubMedDate not supplied

[Sedimentation-biochemical method of determination of sedimentation constants and molecular masses of enzymes].

The sedimentation-biochemical method of determination of enzymes' sedimentation coefficients and estimation of their molecular masses based on the Tiselius' transport technique is discussed. The method permits to determine the sedimentation coefficients of enzyme in the starting mixtures without their preliminary purification. The use of different substrats permits to carry out the studying of several enzymes simultaneously. The frameworks of the method are discussed.

Aspergillus oryzae↗
PubMed2005

Arthrobacter ardleyensis sp. nov., isolated from Antarctic lake sediment and deep-sea sediment.

Three psychrotrophic Arthrobacter strains, isolated from Antarctic lake sediment (An24, An25T) and deep-sea sediment (ZX6) were studied. Their 16S rRNA gene sequences showed highest similarities (97.0-97.9%) with those of A. nicotianae and A. protophormiae. All three strains underwent rod-coccus morphological change, had high mol% G+C content, were aerobic to slightly anaerobic, and grew between 0 degrees C and 30 degrees C, with optimal growth temperature around 25 degrees C. The cell wall peptidoglycan was A4alpha variant. DNA-DNA hybridization, physiological and chemotaxonomic studies indicated that these three strains constituted a new homogeneous genomic species within the genus Arthrobacter, for which the name Arthrobacter ardleyensis, with the type strain An25T (CGMCC 1.3685, JCM 12921) was proposed.

Aerobiosis↗
PubMed2005

Halogenated compounds in a dated sediment core of the Teltow Canal, Berlin: time related sediment contamination.

To study the recent contamination history of DDT (1,1,1-trichloro-2,2-bis(chlorophenyl)ethane) and its metabolites, as well as methoxychlor (1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane), chlorfenson (4-chlorophenyl-p-chlorobenzenesulfonate), and further halogenated aromatics, a sediment core was collected from the Teltow Canal in Berlin (Germany). The sampling site is located nearby a former industrial point source, where recently analyses on pre-samples have indicated high concentrations of halogenated organic compounds. The deposition time of the investigated sediments was determined by gamma-spectrometrical dating. Pollution trends of selected contaminants were attributed to a time period between 5 and 10 years. Concentration profiles reflect not only the recent pollution history of these compounds, but also the time-depending effects of the ban, restriction and termination of DDT-production in the German Democratic Republic (GDR). DDT and other chlorinated aromatic compounds were produced onsite until the late 1980s. Maximum values of 133 mg kg(-1) (dry weight) for p,p'-DDD (1,1-dichloro-2,2-bis(chlorophenyl)ethane) and approximately 100 mg kg(-1) (dry weight) for p,p'-DDMS (1-chloro-2,2-bis(chlorophenyl)ethane), main metabolites of the anaerobic degradation of DDT, were determined. The occurrence of all selected contaminants, most of which have been banned more than 10 years ago, demonstrate recent contamination pathways, and the necessity of a continuous long-term monitoring of the affected environment.

Berlin↗
PubMed2005

The effects of oil exploration and production in the Fladen Ground: composition and concentration of hydrocarbons in sediment samples collected during 2001 and their comparison with sediment samples collected in 1989.

Due to the potentially accumulative nature of the Fladen Ground, an area of intense oil activity in the North Sea, a survey was carried out in 1989 to map the distribution of contamination in relation to these oil activities. All the sediments collected were screened by ultraviolet fluorescence (UVF) for polycyclic aromatic hydrocarbons (PAHs) and selected samples were analysed for n-alkanes (by GC-FID), PAHs and biomarkers (by GC-MSD). This survey was repeated in 2001, with all the 1989 sites being resampled. All of these sediments were analysed for UVF oil equivalents, PAHs, n-alkanes and biomarkers. The concentrations of these parameters decreased between 1989 and 2001, with average decreases ranging from 43% to 88%. In addition, no significant difference was found, for all the parameters, between near field (<5 km from an oil installation) and far field (>5 km from an oil installation) sites in 2001 indicating that the Fladen Ground is approaching a 'steady state' or background concentration for contamination.

Carbon↗
PubMed2006

Sediment quality of the lower St. Johns River, Florida: an integrative assessment of benthic fauna, sediment-associated stressors, and general habitat characteristics.

Sediment quality of the lower St. Johns River (LSJR) estuary, Florida was evaluated using synoptic data on benthic community structure, levels of potential stressors (chemical contaminants, ammonia and sulfide), and other basic habitat characteristics (depth, dissolved oxygen, salinity, temperature) collected at seven stations, three times a year from July 2000-July 2002. Un-ionized ammonia and hydrogen sulfide were detected at toxic levels on at least one sampling occasion at four stations. Chemical contamination of sediment at probable bioeffect levels also was observed at four stations. Concentrations of pesticides or other chemical substances typically associated with human activities (e.g., PCBs) were detectable at all stations, though not always present at concentrations likely of causing significant bioeffects. A total of 251 taxa and 9783 individuals were identified and enumerated from the benthic infaunal samples. Polychaete worms and molluscs dominated the benthic fauna at all seven stations. The opportunistic and pollution-tolerant polychaete Streblospio benedicti was the most abundant species overall (from all samples combined), appearing as a dominant at five of the seven stations. Overall, the sites sampled as part of this study indicate a highly stressed benthos resulting from multiple anthropogenic impacts.

Ammonia↗
PubMed2001

Biomarkers of sublethal stress in the soft-sediment bivalve Austrovenus stutchburyi exposed in-situ to contaminated sediment in an urban New Zealand harbour.

In this study, a suite of sublethal stress biomarkers were analysed in the sediment-dwelling bivalve, Austrovenus stutchburyi, with a view to using them as pollution monitoring tools. Shellfish were transplanted from a relatively uncontaminated site to four sites in a different harbour with different levels of contaminants in the sediment, where they were exposed in-situ for 2 and 8 weeks. A range of sublethal stress biomarkers were selected on the basis of their potential to provide ecologically relevant information (adenylate energy charge, total adenylate nucleotide pool, glycogen and RNA). Adenylate energy charge was lower at contaminated sites after 2 weeks, but recovered after 8 weeks, whereas total adenylate nucleotide pool was depressed after 8 weeks at these sites. Glycogen and RNA were found to be significantly higher at the uncontaminated site after both 2 and 8 weeks. These data suggest the potential application of biomarkers in coastal pollution monitoring.

Adenine Nucleotides↗
PubMed1975

Zeta sedimentation ratio (ZSR), a replacement for the erythrocyte sedimentation rate (ESR).

The zeta sedimentation ratio (ZRS) was evaluated and found to have advantages over the erythrocyte sedimentation rate (ESR). The normal range for the ZSR proved to be 41 to 54%. Elevated ESR's obtained with the modified Westergren technic were also associated with an increased ZSR, except when amenia spuriously elevated the ESR. Reproducibility after storage was slightly better for the ZSR than for the ESR, But for optimal results the test should be performed within two hours of phlebotomy. Increased concentrations od EDTA anticoagulant may falsely elevate the ZSR, especially if the ZSR is initially elevated.

Adult↗
PubMed1990

It is said that elevated erythrocyte sedimentation rate and the elevation of C-reactive protein (CRP) may be indicators of continuing joint destruction in rheumatoid arthritis. What then is the explanation for joint destruction in some patients in whom there is no such apparent elevation of either the sedimentation rate of CRP?

It is said that elevated erythrocyte sedimentation rate and the elevation of C-reactive protein (CRP) may be indicators of continuing joint destruction in rheumatoid arthritis. What then is the explanation for joint destruction in some patients in whom there is no such apparent elevation of either the sedimentation rate or CRP?

Arthritis, Rheumatoid↗
PubMed2002

Determination of the length of sedimentation reaction (erythrocyte sedimentation rate) in non-anticoagulated blood with the Microtest 1.

The erythrocyte sedimentation rate (ESR), now more appropriately referred to as the "length of sedimentation reaction in blood (LSRB)", remains the most widely used laboratory test for monitoring the course of infections, inflammatory diseases and some types of cancer. Thanks to the several recently developed methods for the measurement of this reaction, the safety and reliability of LSRB testing procedures have improved. The method for LSRB measurement recommended by the International Council for Standardization in Hematology (ICSH) and the National Committee for Clinical Laboratory Standards (NCCLS) is based on the traditional Westergren method, using EDTA-anticoagulated samples. The present paper describes and evaluates a procedure for LSRB measurement with a new manual system, the Microtest 1, which requires only 30 microl of blood and is optimal for pediatric use. Microtest 1 results correlated satisfactorily with the ICSH recommended method (r=0.88, 95% CI 0.84-0.91; y=3.45+0.85x), had no significant bias (2.15, 95% CI -0.32-4.63) and had an imprecision of less than 7% for the reference range values. In addition, the results obtained with the Microtest 1 in "native" whole blood were comparable with those obtained with the reference method in K3EDTA and sodium citrate-anticoagulated specimens; (bias = 1.19, 95% CI -1.78 to 4.16 for K3EDTA-anticoagulated samples and bias = 2.43, 95% CI -0.58 to 5.44 for sodium citrate-anticoagulated samples).

Adult↗
PubMedDate not supplied

Comparison of zeta sedimentation ratio with Westergren sedimentation rate.

Zeta sedimentation ratio (ZSR) is a simple, rapid and reproducible test which is not influenced by variables like sex and anemia. There is good correlation with Westergren erythrocyte sedimentation ratio (ESR) in normal and hospital population. Limitation of packing force affects the use of the procedure in polycythemia and in patients with ZSR greater than 80%.

Anemia↗
PubMed2004

Analysis of heterologous interacting systems by sedimentation velocity: curve fitting algorithms for estimation of sedimentation coefficients, equilibrium and kinetic constants.

Analytical ultracentrifugation (AUC) has played and will continue to play an important role in the investigation of protein-protein, protein-DNA and protein-ligand interactions. A major advantage of AUC over other methods is that it allows the analysis of systems free in solution in nearly any buffer without worry about spurious interactions with a supporting matrix. Large amounts of high-quality data can be acquired in relatively short times. Advances in software for the treatment of AUC data over the last decade have eliminated many of the tedious aspects of AUC data analysis, allowing relatively rapid analysis of complicated systems that were previously unapproachable. A software package called sedanal is described that can perform global fits to AUC sedimentation velocity data obtained for both interacting and non-interacting, macromolecular multi-species, multi-component systems, by combining data from multiple runs over a range of sample concentrations and component ratios. Interaction parameters include both forward and reverse rate constants, or equilibrium constants, for each reaction, as well as concentration dependence of both sedimentation and diffusion coefficients. sedanal fits to time-difference data to eliminate time-independent systematic errors inherent in AUC data. The sedanal software package is based on the use of finite-element numerical solutions of the Lamm equation.

Algorithms↗
PubMed1997

Heavy metal distribution in sediments and ecological risk assessment: The role of diagenetic processes in reducing metal toxicity in bottom sediments.

This paper describes the heavy metal distributions in river and lagoonal sediments of Jacarepaguá Basin, Rio de Janeiro, Brazil. The occurrence of metal phase translocation from the reducible to the oxidizable was observed for Fe, Mn and Ni, from the fluvial environment to the lagoonal. Cu was mainly associated with the oxidizable phase while Zn and Pb were mainly associated with the reducible phase in both environments. It has been demonstrated that metal sulfide formation and complexation by organic complexes are very important aspects in terms of toxicity reduction. By means of a risk assessment methodology, based on available sediment data, it was demonstrated that the lagoonal system is exposed to a low potential ecological risk and that Zn was the metal of greater concern with respect to the system pollution.

Journal Article↗
PubMed1994

Rates of benthic protozoan grazing on free and attached sediment bacteria measured with fluorescently stained sediment.

In order to determine the importance of benthic protozoa as consumers of bacteria, grazing rates have been measured by using monodispersed fluorescently labeled bacteria (FLB). However, high percentages of nongrazing benthic protists are reported in the literature. These are related to serious problems of the monodispersed FLB method. We describe a new method using 5-(4,6-dichlorotriazin-2-yl)-aminofluorescein (DTAF)-stained sediment to measure in situ bacterivory by benthic protists. This method is compared with the monodispersed FLB technique. Our estimates of benthic bacterivory range from 61 to 73 bacteria protist h and are about twofold higher than the results of the monodispersed FLB method. The number of nongrazing protists after incubation for 15 min with DTAF-stained sediment is in agreement with theoretical expectation. We also tested the relative affinity for FLB of protists and discuss the results with respect to a grazing model.

Journal Article↗
PubMed2001

Relationships between acute sediment toxicity in laboratory tests and abundance and diversity of benthic infauna in marine sediments: a review.

Acute sediment toxicity tests have become important in regulatory, monitoring, and scientific programs, partly because it has been assumed that they are indicative of ecological damage to benthic infaunal resources. Data from tests of sediment toxicity and measures of benthic community structure were examined from > 1,400 saltwater samples to determine the relationships between acute toxicity and changes in the abundance and diversity of infauna resources. Data were compiled from studies conducted along portions of the Atlantic, Gulf of Mexico, and Pacific coasts of the United States. There was considerable variability among the data sets in the relationships between laboratory results and benthic measures. However, in 92% of the samples classified as toxic, at least one measure of benthic diversity or abundance was < 50% of the average reference value. In 67% of these samples, at least one measure of benthic infauna abundance or diversity was < 10% of average reference conditions. No amphipods were found in 39% of samples that were classified as toxic, whereas amphipods were absent from 28% of the nontoxic samples. In many survey areas, the abundance of crustaceans (notably the amphipods) decreased in the infauna as amphipod survival decreased in the laboratory tests. There appeared to be a break point in the data indicating that, generally, amphipod abundance in the field was lowest when survival in the laboratory tests dropped below 50% of controls. Based on the weight of evidence from all the data analyses, we conclude that ecologically relevant losses in the abundance and diversity of the benthic infauna frequently corresponded with reduced amphipod survival in the laboratory tests.

Animals↗
PubMed2005

Temporal trends in spheroidal carbonaceous particle deposition derived from annual sediment traps and lake sediment cores and their relationship with non-marine sulphate.

Spheroidal carbonaceous particles (SCPs) provide an unambiguous indication of atmospherically deposited contamination from industrial sources. SCP data from a 12 year annual sediment trapping and coring programme at 14 lakes based on the UK Acid Waters Monitoring Network, were used to consider temporal trends in deposition and to compare these with measured non-marine sulphate fluxes. Results show good temporal coherence across a broad area of northern UK and that SCP deposition levels and are now at their lowest since the 1940s, in agreement with modelled sulphate data. SCP fluxes show reasonable linearity with measured non-marine sulphate depositional fluxes from the nearest UK Acid Deposition Monitoring Network sites, especially over the post-flue-gas desulphurisation period, but comparisons prior to 1972 are not possible due to lack of data. We speculate on whether palaeolimnological SCP data might be used to reconstruct the history of non-marine sulphate fluxes from industrial sources.

Carbon↗
PubMed2000

Sediment composition and normalisation procedures: an example from a QUASH project sediment exercise.

The QUASH UE-Project was designed to assess the reliability of normalisation approaches to compensate the influence of natural process affecting the distribution and concentration of contaminants in sediment. The focus of this paper was to test the influence on normalisation procedures of an inorganic matrix using a sample collected in the Venice Lagoon, Italy.

Environmental Monitoring↗
PubMed1988

A comparison of the microerythrocyte sedimentation rate and the macroerythrocyte sedimentation rate methods in pediatric patients.

A comparison of the micro- and macroerythrocyte sedimentation rate methods performed in disposable polystyrene tubes using venous blood from 524 pediatric patients demonstrates an excellent correlation between the methods. The micromethod produces values higher than the macromethod at values above 10 mm/h but this difference is not of sufficient magnitude at the clinical decision level to warrant a change in the traditional reference ranges. The mean difference between the two methods in the 10-25 mm/h range is 1.4 mm/h. The high bias of the micromethod is accentuated in samples with hematocrits less than 30%. The micro- and macromethods do not maintain a constant relationship throughout the range evaluated.

Blood Sedimentation↗